Frank-Walter Steinmeier said Thursday "we are now at perhaps a decisive point" following Putin's meeting Wednesday with Swiss President Didier Burkhalter, whose country chairs the Organization for Security and Cooperation in Europe.

Putin softened his tone on Wednesday, declaring Russia had pulled its troops from the Ukrainian border and calling for a delay of Sunday's referendum on autonomy in eastern Ukraine — though there were no signs either move was happening.

Steinmeier says what was discussed with Burkhalter should "be immediately be put into action."

He says "there is still a chance that we can succeed through diplomatic means to prevent a further escalation of violence."